Again, the invention of this application relates to mounting system and will be described in connection with fixture plates and subplates; however, the invention of this application has a much broader application and can be used in connection with a wide range of quick-change systems and even long-term mounting systems. Mounting systems have been used over the years for a wide range of applications and can be used to quickly and accurately locate and lock a fixture plate or other workholding device to a subplate. Further, additional mounting and/or positioning structures can be used in connection with the workholding system. The above referenced patents, applications and devices show a progression in the art which as led to the invention of this application.
More particularly, it has been found that the LANG workholding system provided improvements in the art for locating and holding a fixture plate to a subplate. However, it has also been found that the LANG system has deficiencies and inefficiencies. In particular, and with reference to U.S. patent application Ser. No. 10/495,076 and U.S. patent application Ser. No. 12/014,236 both to Lang, the mounting systems utilize the ends of the clamping plungers to engage his positioning pins. This configuration has been found to have many deficiencies and inefficiencies. One of these problems is that this design requires a plunger for each positioning pin. Further, by utilizing the end of the plunger for the hold-down engagement, the caroming angles of the system can be to great thereby increasing the force needed to provide the desired hold-down forces and/or increasing the pin diameter of the positioning pins or studs. Including the cam on the end of the plunger also causes the lateral loads on these plungers to be at the end of the plunger wherein the support of these lateral loads can only be from one side of the load. As can be appreciated, this can produce a moment force in the plunger body. These conditions adversely affect the cost of the mounting system, the longevity of the system and the overall performance of the system. Further, it increases the number of parts and machining operations needed to produce the system which can result in quality issues. As a result, these systems can be expensive and they can produce machining variations in operation. Similarly, U.S. Pat. No. 5,167,405 to Cayley. Jr. and U.S. Pat. No. 4,881,727 to Newirovsky use the end of the clamping plungers to engage the positioning pins. As can be seen by all of these discloses, these mounting systems include many parts and require many complex machining operations to produce.